See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Step 1 (Identify the functional groups): The structure shows a terminal alkyne (HC≡C-) at one end and a primary alcohol (-OH) at the other end, connected by a three-carbon chain. Step 2 (Count the total carbon chain): Starting from the hydroxyl-bearing carbon: C1(OH)-C2-C3-C4≡C5. There are five carbons in the longest chain containing both the triple bond and the OH group, giving the parent chain 'pent'. Step 3 (Apply IUPAC numbering priority): The principal characteristic group is the alcohol (-OH), so numbering begins from the end closest to the OH group. Numbering from the OH end: C1 bears OH, C2, C3, C4≡C5. The triple bond is between C4 and C5, and the OH is at C1. Step 4 (Construct the name): Parent chain = pentane → pent; suffix for alkyne = -yn; suffix for alcohol = -ol. Triple bond position = 4, OH position = 1. Name = pent-4-yn-1-ol. Step 5 (Verify): No substituents are present; the chain is unbranched. The name pent-4-yn-1-ol correctly reflects a five-carbon chain with a triple bond starting at C4 and a hydroxyl group at C1. Therefore, the correct answer is pent-4-yn-1-ol.